Hi, I have exactly the same problem, but using the Designer on a PC. It crushes all the time with the same error message, especially when switching between views, or adding some new components to views

I have the same error without switching from PC to MAC. The error occours very often. Most of the times on the 3rd or 4th action. It doesn't event matter what kind of action it is. Sometimes the error occours when changing the current file, when adding a new element to the view or when adding a Controller Reference. In about 5 minutes I have to restart the designer ~9 times.

When I create a new empty project everything works just fine. But when this project gets larger, it fails randomly on different actions. Therefore it's difficult to describe the steps to reproduce. Maybe it doesn't matter, but I am currently using the Designer in trial mode.
Windows 7 64-bit

The error posted above is just a generic error. ANy time a crashing type error occurs this is what is displayed. That being said the above posts could consist of 4-5 different bugs. You are best off posting in your own thread exactly what triggered the error to occur and how you can reproduce it.

Note that in build 286 you are actually able to ignore/recover from bugs like this by clicking Ignore.

I'm getting this error trying to start Designer 2.0.0 beta1

I'm getting this error trying to start Designer 2.0.0 beta1

I'm now getting this error simply trying to start Sencha Designer 2.0.0 beta1. You double-click the program, nothing happens, wait a while, start another program it may/may not start, and sometimes need to click it a third time to get some sort of GUI to appear. No pattern as to which one will show the error but attached is a screen shot. I then close the duplicates and continue on my merry way using the program. I haven't had these "TypeError" messages whilst using the product, though.